The event currently planned for Sept. 22 in Canada was announced several months ago, but now it appears the UFC has targeted a main and a co-main event for the show.

UFC president Dana White confirmed following UFC on FX 3 that the promotion is hoping to lead the card with the heavyweight title rematch between champion Junior dos Santos and Cain Velasquez.

While nothing is a done deal at this point, White stated they are hopeful to have the heavyweight title fight head to Toronto in September.

The last time dos Santos and Velasquez met was in November 2011 with dos Santos coming out on top by knockout at just over one minute into the first round. Since that time, dos Santos defended his title against Frank Mir at UFC 146, while Velasquez came back strong from the defeat and put away former Strikeforce fighter Antonio “Bigfoot” Silva.

In addition to the heavyweights leading the way, the co-main event will feature the return of a future UFC Hall of Famer against one of Canada's youngest and brightest rising stars.

Following a call out by Rory MacDonald just days ago, former lightweight and welterweight champion B.J. Penn accepted the challenge, and now it looks like the UFC is on board as well.

“Yeah, we're going to do it,” White said about Penn vs. MacDonald. “Joe (Silva) is calling B.J. and his crew tonight to make sure that was the case, and then that fight's going to happen.

“It will happen on the Toronto card, probably be the co-main event.”

It will be Penn's first fight back since announcing his retirement following a loss to Nick Diaz at UFC 137 last year.

Look for UFC officials to make official announcements about the card in the coming weeks.